Door closing device



Feb. 22, 1944. 1.. RICHARDSON 5 3 DOOR CLOSING DEVICE Filed June 17,'1941 '4 Sheets-Sheet l A ldwrenaejladardfan Feb. 22, 1944. L. RICHARDSON2,342,428

noon CLOSING DEVICE Filed June 17, 1941 4 Sheets-Sheet 2 Feb- 22, 1944-L. RICHARDSON 2,342,428

DOOR CLOSING DEVICE 7 Filed Jun e 17, 1941 4 Sheets-Sheet s avwe/wfoaFeb. 22, 1944. L. RICHARDSON 2,342,423

. DOOR CLOSING DEVICE Filed June 17, '1941 4 Sheets-Sheet 4 awed/wan.

Patented F eb. 22, 1944 UNITED STATES PATENT OFFICE 23 Claims.

This invention relates to door closers, and more particularly to a doorcloseremployingunique spring means adaptedto be energized during openingof the door andtobe oontrolledso as to rovide potentialenergytoeffectclosing of. said door at diiierent rates during difierentjportions ofits closing movement.

In the usual spring t me of door closing devices or mechanisms thespring means has "a closingforce equal to the force applied to open thedoor, minus any friction losses that occur in the mechanism. Thegreatest force required to closethe door must bepresent in the last fewdegrees of closure and, therefore, the greatest and equal'effort must beexerted or applied at the beginning of the opening movementof the door.This opening force is often so'great, especialh! with respect to thedoors of sleeping cars, that it requires an unusuahexertion on the partof the person attempting to open the door. most common method sofardevised of reducing theopening force is to construct the closing deviceso as to require little opening force and permit the door to closerapidly, utilizing the dynamic energy of the door to build up-a highstatic force efiective at the end of the closing movement of the door tolatch the same. This efiect is referred to as slamming the door shut.Such devices, however, aredangerous'and the fingers of man persons havebeen injured by being caught between the edge of the door and the jambasthe door slammed shut.

Outside of the relatively last few degrees'of closing movement of thedoor, only a small'force is usually needed to move the door towardclosed position. Hence, the ideal doorclosing device is one whichrequires: a moderate-opening-force,-a small closing force from its fullopen position to withina few degrees of closure, and a relatively largeforcefro-m that point to closed position so that the latching of thedoor will be assured without any slamming effect. The presentinventionis so arranged and constructed-that it ful fills all of the aboverequirements.

It is well known' that one of themost positive means of storing energyis a spring; In the'construction of the present door closer, a suitablemain spring is wound during opening movement of the door to storepotentialenergy-therein to subsequently effect closingof the' door. Arelatively small auxiliary'spring isarrangedso that it is Wound during aportion'orthe'closing'move ment of the door, the energy for "windingsaid auxiliaryspring being robbed fromthe-potential' energy of the mainspring, with the result The that the door is caused to close'ata'slowed-rate while the auxiliary-spring is'being wound. Thus, duringthe winding of the auxiliary spring, the net closing force is thedifierence between the energy of the main spring and thatdiverted towind the auxiliary spring. The arrangement is al'sosuch that theenergy'stored'in'the'auxiliary spring is released or discharged as'thedoornears its fully closed position so that this energy is madeavailable to'supplement that remaining'in the main spring to increasethe closing rate of the door and cause it to close with sufficient forceto'assure latching. In other'words, the net closing' force available-atthe moment of'closing is the sumof the energy absorbed by theauxiliaryspring plus thepotential energy remaining inthe main spring, so that arelatively high closing'force is made available'to latoh'the door.

One of the principal objects of the invention is to provide adoorclosing mechanism which will enable adoor to be opened with a minimum ofeffort but which will provide all of'the force necessary at the end-ofthe closing movement of the door to efiect latching of the door inclosed position.

Another object of the invention is toprovide a door closer arrangedso'that it will cause'a door to close at a slowed-rate untilthe-doorreaches its nearly fully closed posit'ion and will then effectanincrease in the'closingrateof'the door sufficient to provide latching.

Another object of the invention is to'provide-a door closer arrangedsothat it will eliminate the danger or" injuring the fingers of a person,should they be positioned between'the door and ja'mb as the door closes.

A further object of the invention is to provide a spring type doorcloserhaving'mean's' for adjusting the tension of the spring means asrequired-for a given installation.

Still another object of the invention is to provide a door closeradapted to receiv one or more springs suitable for controlling theclosing of doors-of varioussize and weight, and whose initial tensionmay be varied as required.

A still further object of the invention is to provide a door closerwhich is.relatively simple in construction and inexpensivetomanufacture.

Other and further ob'ie'cts'of the invention will be apparent from thefollowing description'taken in conjunction'with the accompanyingdrawings, in'which:

Fig. 1 is'a 'fragmentary-elevational view ofia door closer mechanismembodyingthe'principles of thepresentinvention and showing one *wayotoperatively connecting the same with a door and door jamb;

Fig. 2 is a somewhat schematic plan View of the door closer shown inFig. 1;

Fig. 3 is an enlarged plan viewro-f the portion of the door closer whichis preferably mounted upon the door;

Fig. 4 is a sectional view taken on the line 5- 6 of Fig. 3;

Fig. 5 is a bottom plan view of the door closer;

Fig. 6 is a somewhat diagrammatic view showing the operative relation ofthe parts comprising the door closer when the door is in its nearlyfull-open position, the main spring at this time being already wound;

Fig. 7 is a similar view showing the relative position of the parts ofthe door closer when the door is about half-closed, that is, onan angleof about 45, or at the time winding of the auxiliary spring commences;

Fig. 8' illustrates the parts of the door closer mechanism when the dooris in about the 80 position of its closing movement or while theauxiliary spring is being wound; and

Fig. 9 shows the relationship of the parts and the door when the door isnearly fully-closed, thatis, when it is within about 5 of its fullyclosed position and the auxiliary spring is unwinding.

Referring now to Figs. 1 and 2, the door closer is generally indicatedby the letter D and comprises a casing I having laterally extendingflanges 2 adapted to be secured to the upper end of a door 3 by anysuitable fastening means such as screws 4. The door closer D includes amain shaft 5 to which is connected one end of an actuating lever 6, apin 6 securing the same in assembled relation with said shaft. Theopposite end of the lever B is pivotally connected by a pin 7 to one endof a link 8, and the opposite end of said link is pivotally connected bya pin 9 to a bracket ||l suitably mounted upon the trim surrounding thedoor 3. The door 3 in turn is pivotally mounted upon hinges |2, one ofwhich is shown in Fig. 1, it being understood that a suitable number ofadditional hinges are provided to properly support the weight of thedoor.

Referring now to Fig. 4, the door closer casing ihas a flange |3 at itsupper end surrounding a plain circular opening I4 and a flange it at itslower end surrounding a threaded opening it. A chamber I! for a mainspring I8 lies between the flanges 3 and I5, and a relatively smallchamber IQ for an auxiliary spring 29 is arranged at one side of thechamber IT. A cover plate 2| forms a closure for the chambers l1 and i9and is secured in place by machine screws 22 circumferentially spaced,as best shown in Fig. 3. The plate 2| is apertured at 23 for thereception of a reduced portion 24 formed at the upper end of the mainshaft 5. The lower end of the shaft ,5 extends through an aperture 25formed in a circular plug 26 threadedly mounted in the opening l6. Oneend 21 of the main spring |8 extends through an opening 28 in the mainshaft 5 and the opposite end 29 of said main spring extends through anopening in the'plug 26 as best shown in Fig. 4.

The plug 26 is provided with a central hexagonal boss 3| (Fig. 5)adapted to be engaged by a suitable wrench to effect adjustment of saidplug in the threaded opening l6. A series of circumferentially spacedaxially extending notches 32 is formed inthe periphery of the plug 25. Alocking screw 33 having a reduced plain end 34 of approximately the samecircumferential width as the notches 33 is threadedly mounted in anopening 35 extending radially through the flange l5 so that the plug 26may be rotated to place a desired initial tension in the main spring |8,and locked in the desired position of adjustment by rotating the lockscrew 33 sumciently to engage the reduced extension 34 with one of thenotches The door closer D also includes an auxiliary shaft 31 (Fig. 4)having a reduced extension 38 at its upper end projecting through anaperture 39 in the cover plate 2|. The lower end of the auxiliary shaft31 projects through an opening 40 in a plug 4| threadedly mounted in anopening 42 in the casing The upper end of the auxiliary spring 20extends through a transverse opening 43 in the auxiliary shaft 31 andthe lower end of said auxiliary spring extends through an opening 44 inthe plug 4|. The plug 4| includes a. central hexagonal boss 46, andperipheral notches 4'! similar to those provided in the plug 26, wherebythe plug 4| can be turned to adjust the tension of the auxiliary spring20. A locking screw 48 is threadedly mounted in an opening 49 in orderto provide for locking of the plug 4| in adjusted position in the samemanner described in connection with the tensioning of the main springIS.

A cam-carrying plate 5| (Fig. 4) is non-rotatably mounted upon thereduced portion 24 of the main shaft 5 and is secured in position abovethe cover 2| by a pin 52 so that said cam plate and shaft rotate as aunit whenever the lever 6 is turned during the opening and closingmovements of the door 3. For convenience in illustration andexplanation, the parts in Figs. 1 and 3 have been shown in the positionthey assume when the door is in its fully closed position. On the otherhand, Fig'. 6 shows the door 3 in its nearly full-open position. It willbe apparent from a comparison of these figures that during the openingmovement of the door, the lever 6 is rotated in a counterclockwisedirection relative to the casing I, thereby effecting winding of themain spring 3 and the storing of potential energy in said spring toeffect a return or closing of the door; the cam plate 5| being rotatedthrough the same angle as the lever 6 because both are fixed to the mainshaft 5. The return rotational movement of the cam plate 5| is utilizedto effect winding of the auxiliary spring 20 through cam elementscarried by said plate and generally indicated by 53 and 54, respectively(which Will be described in detail later); it being understood thatduring the closing movement of the door 3 the main spring I8 tends torotate the lever 5 and cam plate 5| in a clockwise direction. Hence, itwill be apparent that any energy transmitted through the cam plate 5| toeffect winding of the auxiliary spring 29 (as described hereinafter)will require the door 3 to close at a slowed-rate.

An arm 55 is secured by a pin 56 to the reduced portion 38 of theauxiliary shaft 37. The tendency of the auxiliary spring 29 is to rotatethe arm 55 in a clockwise direction as viewed in Fig. 3 and a stop 51 istherefore mounted on the cover plate 2| to limit the angular movement ofthe arm 55 in said direction.

The arm 55 is generally triangular in shape, as best shown in Fig. 3,and the apex of said arm may be said to be fixedly secured to theauxiliary shaft 3'! with the corner portions 58 and 59 of said armdisposed on opposite sides of the main ment.

shaft5. The portions 58 and 59 carry a roller 50 and respectively,suitably mounted "upon small conventional ball bearings (not shown) toreduce friction, said rollers being operative'ly mounted by thescrews-62 and fi3. Thebase of the triangular arm 55 is cutawayas-indicated at 64 to provide for limited angular movement of saidarmwith respect to the hub portion of the cam plate 5|. In thisconnection it will be noted that the-axis of the rollers 60 and 6respectively, and the axis of the main shaft 5, all lie the samedistance from the axisof the:auxiliary shaft 31. This arrangement 1precludes binding of therollers 60 and 6 and cam elements 53 and 54.

The cam elements 53 and 56, carried by the cam plate 5|, are so shapedas-to provide-for complemental engagement with the rollers 50 and 6!carried by the arm-.55, whichser-ves to wind the tauxiliaryspring 20.Thecamt element 53 includes an inner concentric portion 65 and an outerconcentric portion 6.6,rbot-h ofwhich are cooperable with. theroller61.. The-portions 65 and 55 are connectedbyacamsurfacefi! adapted toengage with the roller 6| to elfect winding of the auxiliary springduring the-closing movement of the door, asbest illustrated in Fig. 8,and a cam surface .63 adapted to engage with said. roller to control theunwinding of saidauxiliary spring when the door 3 has reached itsnearly-closed position, as best illustrated .inFig. 9. The outerconcentricportion 66 provides a dwell between winding and release .orunwinding .of the auxiliary spring 120, so that the release can bedesigned to .occurat any desired angle, say, 10 before thedoor.3.reaches.its.fully closed position.

The cam element 54-is, alsolprovidedzwith.concentric surfaces 69 and 10which are cooperable with the other roller 60. A.canr. surface 7|connects the concentric portions .69 and 1.0 and is adapted to engagethe roller 60. during the winding movement of the arm..55,1as bestindicated in Fig. 8. As has beenpreviously. stated, the roller 6| atthis. time is engaged. with the cam surface 5'! and, therefore. thecanhsurfaces H and El mutually cooperate to effect winding of theauxiliary. spring 20. Theconcehtriopontions 89 and to of the camelement54are'also connected by a cam surface 12 cooperabie with the roller (50when the auxiliary spring 20.is:unwinding and the door 3 is inits nearlyfullyclosed position, asillustrated inFigQQ. Theroller 6! is now engagedwith the cam surface 58 and aids in rotating the cam. plate 5| and lever6 to increase the closing rate of the door toassure latching.

In order to permit movement of the cam ele-. ment 5d past the roller 60and. in order to .pick up the roller 55 to elfect winding of theauxiliary spring 7.0. as when the cam plate 5| is moved from theposition shown in Figs. 1 and 3 to that shown in Fig. 6, a, latch 13 ispivotally mounted upon the cam element 54 at one end of the concentricsurface fifi by apin M. The cam element 54 is cut away to provide-aradial shoulder 15 and the latch 13 is provided with an end surface isadapted to engage said shoulder to prevent relative rotational movementof'said latch in one direction relative to said cam ele- The surface 16is yieldablyv retained in engagement with the shoulder 15 by a sprinstrip 1'! anchored at one endto'the underside of the cam plate 5| byarivetflis; the opposite end of said spring strip engaging. a pin,Taxcarried by said latch andpextendmg through an arcuate slotBOIinsaid'campIate.

During the opening movement of the door 3, orin other words, during themovement of the door from the closed position shown in Figs. 1

and 3 to the nearly full-open position shownin Fig. 6, the lever Granditsassociated cam p ate 5|. are rotated ithroughfaniangle .suchthat thecam element 54 andthe latch." are carried .past the roller 6|];TheJpiVQtal andzyieldable mounting: for the latch: 13 just described,permits said latch to move inwardly totthe position shownrindot-'and-da'sh lines in 'Fig; 6 'wherefromi it will be apparent that thelatch 13. can be pivotedinwardlyabout: the .pinh'l'd to clear the roller60. without. in any wayinterferingwith the rotary. movement: of the camplate. 5|. It will be noted from Fig,fijthatneitherof thedollers 50 and6| is engaged by the: cam elements 53 and 54: when the door: is nearlywide open. However; as the door 3'v closes, "and particularly when itreaches about;.the,half-closed'or45 position, shown in Fig; 7,thelatch'la will engage with the roller 60. and cause it to ride up ontothecam surface 1|, asshown in Fig. 8. Assoon as the roller 50 isengagedjby the latch 13, the arm 55 is caused to rotate counterclockwiserel-- ative to the casing and the-winding of'the-auxiliary spring 20commences. The. energy for suchwindingis diverted. from the main spring|8, which was previously wound during the opening movement of the door-3: to store energy thereinior efiectingclosing of said'door. Thus, partof the closing energy of themain spring H3 is transferred to theauxiliary spring 20 so that less energy is available to return or. closethe door during, this particular part of its movement and, accordingly,thedoor moves toward closed position at asloWed-rate. As the winde ingaction of the auxiliary spring 29' continues, the roller 6| engages thecam; surface 67 so that both cam elements 53 and 54' now cooperate toeffect winding of the auxiliary spring. Winding continues untiltherollerv Strides onto the concentric: surface .66; whereupon-g no furtherwinding of the auxiliary spring 2|] occursfor about 10 ofclosing'movement of: the (1001,01' until. theroller 6| rides. off theconcentric surface 66 onto the canrwsurface B8. The auxiliary: spring 20isthenfree to unload. or unwind and the released energy of.saidauxiliar-y spring is now made available to aid (the main spring l8)in returningthe arm 55in a. clockwise direction, thereby causing theroller '6| to bear against the cam surface 68: and the-roller 6|! tobear against the cam surface |2so as to exert apositive closing forcethrough the lever B to effect sudden closing of the door 3' at the endof its closing movement. Thus, the remaining energy of the main spring.|"8-"normally tending to elfect closing of the-door is:suddenly'supplemented by. thepotential energyv of the auxiliaryspring!!! so that the door :closes at a more rapid rate at the end'ofits closing movement. This increased rate of closing movement is suchthat positive latching of the .door C-Lmust take place.

If the door should be pushediopenagain before it has fully closed,lnoharm or'injury can occur to the parts and particularly. the .cam. androller elements inasmuch as their arrangement permits the same to bebacked up-or reversed. in theiraction by the openingforce applied to thedoorwhich counteractsthelclosingiorce of the spring or springs.

It, will; be rapparent thati the iprinciples :of the invention disclosedherein may be embodied in devices varying in construction from thatdisclosed in detail herein without departing from the spirit of theinvention or the scope of the same; a main shaft connected with saidmain spring to effect further. winding thereof and storage ofclosingenergy therein during the opening movement of said door; an auxiliaryshaft connected with said auxiliary spring to effect winding thereofduring the closing move ment of said door; a cam plate non-rotatablysecured to said main shaft; 21. pair of cam elements carried by said camplate, one of said cam elements including a spring-pressed latch; awinding arm non-rotably secured to said auxiliary shaft; a pair ofrollers carried by said winding arm, one roller being adapted to beengaged by each of said cam elements; stop means for positioning saidwinding arm in a predetermined initial position such that said latch canengage one of said rollers to start further winding of said auxiliaryspring and absorb a part of the closing energy of said main springduring a part of the closing movement of said door to thereby cause saiddoor to move toward closed position at a slowed rate, each of said camelements having a cam surface adapted to engage with one of said rollersto effect continued winding of said auxiliary spring while said door isclosing and a cam surface to permit unwinding of said auxiliary springor discharge of the energy absorbed by said auxiliary spring from saidmain spring as said door reaches its nearly fully closed position,whereby the energy absorbed from said main spring by said auxiliarlyspring to effect a slowed closing rate is made available to supplementthe remaining energy of said main spring to increase the closing rate ofsaid door just as it reaches the end of its closing movement.

A door closing device comprising: means arranged to store a part of theenergy expended during the opening movement of a door for use ineffecting closing of said door; and substantially friction free meansfor absorbing a portion of said closing energy so that said door movestoward closed position at a slowed closing rate and for discharging saidabsorbed energy just as said door is about to completely close, wherebyto then increase the energy tending to close said door to assurelatching.

3. A door closer comprising: a casing adapted to be mounted upon a door;a main spring in said casing; an auxiliary spring in said casing; meansfor winding said main spring during opening movement of said door; andmeans for utilizing the energy of said main spring to effect winding ofsaid auxiliary spring during a part of the closing movement of saiddoor, said last mentioned means being arranged to permit unwinding ofsaid auxiliary spring and the release of its energy as said door reachesits nearly fully closed position.

4. A door check comprising: a casing adapted to be mounted upon a door;a main spring in said casing; means for adjusting the initial tension ofsaid main spring; an auxiliary spring in said casing; means foradjusting the initial tension of said auxiliary spring; means foreffecting winding and further tensioning of said main spring duringopening movement of said door; and means for utilizing the energy ofsaid main spring for effecting winding of said auxiliary spring duringclosing movement of said door, said last-mentioned means being arrangedto release the energy of said auxiliary spring as said door nears theend of its closing movement.

5. A door closer adapted to be operatively associated with a doorincluding: means arranged to have energy stored therein duringtheopening movement of said door to provide potential energy foreffecting closing of said door; substantially friction free means forabsorbing a portion of the closing energy of said first-mentioned meansduring a part of the closing movement of said door so that said doorwill close at a slowed rate; and means for effecting a release of saidabsorbed energy as said door reaches its nearly fully closed position,whereby to supplement the remaining potential energy of saidfirstmentioned means and assure latching of said door.

6. A door closer adapted to be operatively associated with a doorcomprising: means arranged to have energy stored therein during theopening movement of said door to provide potential energy for effectingclosing of said door; and a substantially friction free mechanismincluding means for absorbing a portion of the closing energy of saidfirst-mentioned means during a part of the closing movement of said doorso that said door will close at a slowed rate, said mechanism beingarranged to release said absorbed energy as said door reaches its nearlyfully closed position, whereby to supplement the remaining potentialenergy of said first-mentioned means and assure latching of said door.

7. A door closer comprising: a casing adapted to be mounted upon a door;a main spring in said casing; an auxiliary spring in said casing; meansfor winding said main spring during the opening movement of said door;and means utilizing the energy of said main spring for efiecting windingof said auxiliary spring during closing movement of said door, saidlast-mentioned means being arranged to permit unwinding of saidauxiliary spring as said door reaches its nearly fully closed position.

8. A door closer adapted to be operatively associated with a doorcomprising: a windable spring arranged to be wound to store energytherein during the opening movement of said door to provide potentialenergy for effecting closing of said door; means for winding said springduring the opening movement of said door; and a mechanism including awindable auxiliary spring for absorbing a portion of the closing energyof said first-mentioned spring during a part of the closing movement ofsaid door so that said door will close at a slowed rate, said mechanismbeing arranged to release the energy absorbed by said auxiliary springas said door reaches its nearly fully closed position, whereby tosupplement the remaining potential energy of said first-mentioned springand increase the closing rate of said door.

9. A door closer comprising: a casing having a plurality of chambers; amain spring in one of said chambers; an auxiliary spring in another ofsaid chambers; a main shaft arranged to effect winding of said mainspring; an auxiliary shaft arranged to effect winding of said auxiliaryspring; alever; secured-to said mainshaft and arranged; to rotat the.same to. effect windin of said main spring, during opening movement ofsaid, door; andcam means interposed between said main shaft andauxiliary shaft arrangfid to. effect winding and discharge of saidauxiliary spring during the closing movement. of said door.

10. A door closer; comprising: a casing; having a large chamber and arelatively, small chamber; a main springin said large cham ber; anauxiliary spring in said relatively small ohamberi. amain shaft in saidlarge chamber; one end of; saidmain spring being connected with saidmain shaft and e pp en of sa main: spri ein onnected with said casing;an auxiliary shaft; in said small chambcn One end of said,;auxilia-ryspring being connected with said; auxiliary shaft and the opposite endof said auxiliary springbeing connected with said casing; a. leversecured nected with said main: shaft, and the opposite end of said mainspring being connected with the adjusting means for said main spring; anauxiliary shaft in said small chamber, one end of said auxiliary springbeing connected with said auxiliary shaft and the opposite end of saidauxiliary spring being connected with the adjusting means for saidauxiliary spring; a lever secured to said main shaft arranged to effectwinding of said main spring during opening movement of said door; andmeans interposed between said main shaft and auxiliary shaft arranged toeffect winding and release of said auxiliary spring during the closingmovement of said door.

12. A door closer comprising: a generally cylindrical casing adapted tobe mounted upon a door, said casing having an open ended chamber formedtherein; a threaded plug closing one end of said chamber; a closureplate closing the opposite end of said chamber; a shaft extendingaxially across said chamber having portions rotatably mounted in saidplug and cover plate, respectively; a windable spring in said chamber,one end of said spring being connected to said shaft and the oppositeend of said spring being connected to said plug, the lpheripheral edgeof said plug being provided with a series of circumferentially spacednotches; a locking screw carried by said casing and having an endportion adapted to extend into one of said notches to lock said plug inadjusted position; and a lever connected to said shaft to effectrotation of said shaft and winding of said spring during openingmovement of said door.

13. A door closer comprising: a casing adapted to be mounted upon adoor; a main spring in said casing; an auxiliary spring in said casing;mean including a main shaft for effecting winding of said main springduring opening movement of said door; a cam plate non-rotatably securedto said main shaft, a cam element mounted upon said cam plate; and meansfor effecting winding of said auxiliary spring including an auxiliaryshaft, an arm non-rotatably secured to said auxiliary shaft and arollercarried by said arm cooperable with said cam element 14. A door closeradapted to; be mounted upon a door comprising: a main spring; arotatable main shaft arranged to effect winding of said main springduring opening movement of said door; an auxiliary spring; a rotatableauxiliary shaft adapted to efiectwinding of said. auxiliary spring; acam element rotatable with said main shaft; a winding arm non-rotatablysecured to said auxiliary shaft; and; a roller .carried by said windingarm cooperable with said cam element, said cam element including a camsurface adapted to engage saidrrollerto. effect winding of saidauxiliary spring and a second cam surface adapted. to permit unwindingof: said auxiliary spring.

15. A door closer adapted to belmounted upon a door comprising: awindablemainspring; a rotatable main shaft arranged toefiectiwinding ofsaid main spring during opening movement of said door; agwinda ble.auxiliary. spring; a rotatable auxiliary shaft adapted. to effectWinding of said auxiliary spring; a. cam element. rotatable with saidmain shaft; a winding-Harm none rotatably secured to said auxiliaryshaft; and a roller carried by, saidwinding arm cooperable with saidcamelement, said cam element comprisinga concentric portion, acamsurfaceadaptedrto engage saidroller to effect; winding of said auxiliaryspring, second cam. surface adapted to permit unwinding of saidauxiliary spring, and a latch pivotally mounted at one end of saidconcentric portion and arranged to engage said roller during rotation ofsaid main shaft in one direction to cause said roller to ride up ontosaid first-mentioned cam surface to effect winding of said auxiliaryspring during unwinding of said main spring.

16. A door closer comprising: a casing adapted to be mounted upon adoor; a main spring in said casing; an auxiliary spring in said casing;means including a main shaft for effecting winding of said main springduring opening movement of said door; a cam plate non-rotatably securedto said main shaft; a plurality of cam elements mounted upon said camplate; and means for effecting Winding of said auxiliary springincluding an auxiliary shaft, an arm non-rotatably secured to saidauxiliary shaft, and rollers carried by said arm, one roller beingcooperable with each of said cam elements.

17. A door closer comprising: a casing adapted to be mounted upon adoor; a windable main spring in said casing; a windable auxiliary springin said casing; a main shaft connected with said main spring to effectwinding thereof during opening movement of said door; an auxiliary shaftconnected with said auxiliary spring; a cam plate non-rotatably securedto said main shaft; 2. pair of cam elements carried by said cam plate; awinding arm non-rotatably secured to said auxiliary shaft; a pair ofrollers carried by said winding arm, one roller being adapted to beengaged by each of said cam elements; means for positioning said windingarm in a predetermined initial position such that said cam elements canengage said rollers, each of said cam elements having a cam surfaceadapted to engage with a roller to effect winding and to permit releaseof said auxiliaryv spring during the closing movement of said door. i

18. A door closer comprising: a casing adapted to be mounted upon adoor; a windable main spring in said casing; adjustable means forwinding said main spring to initially tension the same; a windableauxiliary spring in said casing; adjustable means for Winding saidauxiliary spring to initially tension the same a main shaft connectedwith said main spring to effect further winding thereof during openingmovement of said door; .an auxiliary shaft connected with said auxiliaryspring;-a'cam plate no'n-rotatably secured to said main shaft; a pair ofcam elements carried by said cam plate; a winding arm non-rotatablysecured to said auxiliary shaft; a pair of rollers carried by saidwinding arm, one roller being adapted to be engaged by each of said camelements; stop means for positioning said winding arm in a predeterminedinitial position such that said cam elements can engage said rollers,each of said cam elements having a cam surface adapted to engage with aroller to efiect winding and to permit release of said auxiliary springduring the closing movement of said door.

19. A door closer comprising: means arranged to have energy storedtherein during the opening movement of a door; and means for absorbing aportion of the energy stored in said first-mentioned means and thenreleasing the absorbed energy derived from said first-mentioned meansduring the closing movement of said door.

20. A door closer comprising; a casing adapted to be mounted upon adoor; a windable coil spring in said casing; means for winding said coilspring during the opening movement of said door to store closing energytherein; and means for absorbing a portion of the energy stored in saidcoil spring and then releasing the absorbed energy derived from saidcoil spring during the closing movement of said door.

21. A door closer comprising: means arranged to have energy storedtherein during the opening movement of a door; and means for absorbing aportion of said energy and then releasing the absorbed energy derivedfrom said first-mentioned means during the closing movement of saiddoor, said energy absorbing occurring only during a portion of saidclosing movement of said door.

22. A door closer comprising: a casing adapted to be mounted upon adoor; a windable coil spring in said casing; means for winding said coilspring during the opening movement of said door to store closing energytherein; and means for absorbing a portion of said energy and thenreleas ing the absorbed energy derived from said coil spring during theclosing movement of said door, said energy absorbing occurring duringonly a portion of said closing movement of said door.

23. A door closer comprising: means arranged to have energy storedduring the opening movement of a door; and means for absorbing a portionof said energy and then releasing the absorbed energy derived from saidfirst-mentioned means during the closing movement of said door, saidabsorbing and releasing means including means arranged and constructedso that the absorption of energy commences when said door is about 45from closed position and the release of the absorbed energy occurs whenthe door is about 10 from closed position.

LAWRENCE RICHARDSON.

